Underwater or land-based pipelines intended to convey fluids (such as aqueducts for water and oil pipelines) or gas undergo thermal, physical or chemical attacks that cause damage. Repairing this damage is costly. These pipelines generally have a substantially circular section.
Repairing such a pipeline may be done via various techniques, such as welding or fastening a sleeve and/or completely replacing a segment. The major drawback of replacing pipeline segments is that they are restrictive to use, since they require stopping the flow of the internal effluent such as liquid, gas or other mixtures, in the portion of the pipeline to be repaired. Rehabilitation techniques from outside the pipelines make it possible to avoid replacing the pipeline segment.
Documents FR 2,666,864 and EP 0,548,231 are known, which describe a system for unwinding, on a pipeline, a tape made up of fibers embedded in thermoplastic material that is melted before placing the tape on the pipeline. Such tape may not ensure good sealing due to the plasticity itself of its material. Furthermore, in underwater environments, heating of the tape is particularly delicate and irregular. The homogeneity flaws of the elasticity thus obtained increase the fragility of the repair. The elasticity of the thermoplastic tape limits the use of this system to repair pressurized pipelines. Lastly, this document describes the assembly of successive contiguous turns, which necessarily have a sealing weakness at their border.
These documents describe, regarding the assembly on the pipeline, a system formed from a first horseshoe-shaped part that is placed on the pipeline and that bears at least three motors to rotate, relative to the axis of the pipeline, inside it, a second circular part until it again touches the first part while having bypassed the pipeline. This complex system has problems with superposition or separation of the tape if it is not perfectly centered. It is furthermore particularly delicate and complex to implement and subject to vibrations due to the weak anchoring of the two parts relative to one another. Lastly, the system is not compatible with the parts of underwater pipelines commonly called risers, bent bars, and splash zone.